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®
Bendix
MC-11
®
™
DELIVERY
FIGURE 1
DESCRIPTION
The Bendix
MC-11
tractor antilock assembly is designed
®
™
to improve vehicle stability by reducing wheel lock-up during
aggressive braking. Like the MC-10
it replaces, the MC-11
™
one-channel system–it uses one modulator. And the system
can control single or tandem axles. The antilock assembly
mounts to the vehicle frame and usually replaces the drive
axle service relay valve.
The MC-11
tractor antilock assembly consists of an EC-11
™
electronic controller and an M-12
controller houses the electronics that regulate the antilock
system. The electronics are protected by a self-healing
silicone compound. The EC-11
diagnostic window and reset switch, and its 14 pin connector
is the electrical link to the rest of the antilock system. (See
Figure 2.) The controller mounts to the modulator with four
cap screws, and it is electrically connected to the modulator
Tractor AntiLock
14-PIN
CONNECTOR
CONTROL
antilock assembly that
™
tractor antilock assembly is a
™
modulator. The EC-11
controller contains a
™
LED DIAGNOSTIC
DISPLAY
SUPPLY
with a four-pin connector. The M-12
components: solenoids, which rapidly apply and exhaust
air during an antilock stop, and a standard relay valve. (See
SD-13-4772 for more information on the M-12
The air connections for the MC-11
are as follows:
AIR CONNECTION
™
™
Supply
(to reservoir)
Delivery
(to brake actuator)
Control
(to rear service brake valve delivery)
EC-11
™
CONTROLLER
M-12
™
MODULATOR
DELIVERY
™
modulator has two
modulator.)
™
™
tractor antilock assembly
EMBOSSED
IDENTIFICATION
SUP
DEL
CON
1
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Related Manuals for BENDIX MC-11 TRACTOR ANTILOCK
Summary of Contents for BENDIX MC-11 TRACTOR ANTILOCK
- Page 1 DELIVERY FIGURE 1 DESCRIPTION with a four-pin connector. The M-12 ™ modulator has two The Bendix MC-11 tractor antilock assembly is designed ® ™ components: solenoids, which rapidly apply and exhaust to improve vehicle stability by reducing wheel lock-up during air during an antilock stop, and a standard relay valve.
- Page 2 14 PIN CONNECTOR CALLOUTS CONNECTION “+” POWER RETARDER DISABLE “-” GROUND DASH LIGHT SERIAL LINK SERIAL LINK UNUSED UNUSED UNUSED UNUSED SENSOR SENSOR SENSOR SENSOR 14-PIN CONNECTOR EXH. BLK. GRD EXH. BLK. PWR EXH. WHT. GRD EXH. WHT. PWR GROUND POWER SENSOR RETARDER...
- Page 3 DOUBLE CHECK VALVE TRAILER CONTROL EXHAUST VALVE SOLENOID BRAKE VALVE CONTROL INLET SOLENOID PISTON RESERVOIR DELIVERY SUPPLY BRAKE EXHAUST CHAMBER FIGURE 3 - APPLYING: NORMAL SERVICE APPLICATION PIN E - The serial link allows the EC-11 controller to “report” ™ its operating PIN IF condition to a specialized The wiring connections on the 14 pin connector are as external computer in response to certain commands...
-
Page 4: Operation
DOUBLE CHECK VALVE TRAILER CONTROL EXHAUST VALVE SOLENOID BRAKE VALVE CONTROL INLET SOLENOID PISTON RESERVOIR DELIVERY SUPPLY BRAKE EXHAUST CHAMBER FIGURE 4 - BALANCED POSITION which passes through the open inlet solenoid and into the solenoid housing and out the exhaust port of the brake valve. control cavity of the relay valve. -
Page 5: Leakage Test
DOUBLE CHECK VALVE TRAILER CONTROL VALVE EXHAUST BRAKE SOLENOID VALVE CONTROL INLET SOLENOID PISTON RESERVOIR DELIVERY SUPPLY BRAKE EXHAUST CHAMBER FIGURE 5 - EXHAUSTING: NORMAL SERVICE APPLICATION 1. Remove any accumulated contaminants and visually 5. If leakage is excessive around the supply and exhaust inspect the exterior of the unit for excessive corrosion or solenoids, replace the M-12 modulator. - Page 6 Always wear safety glasses. system pressure has been depleted. 2. Stop the engine and remove ignition key when 8. Use only genuine Bendix replacement parts, ® working under or around the vehicle. When components and kits.
- Page 7 However, overclamping ASSEMBLY will result in damage, leakage, and/or malfunction. If a vise 1. Using a lubricant (Bendix Pc. No. 291126) lightly coat is to be used, position the MC-11 assembly so the jaws ™...
- Page 8 CAP SCREW FIGURE 7 - EXPLODED VIEW...
- Page 9 6. Install o-ring(5) into its groove in the piston(6). Install piston(6) into the M-12 modulator body. The piston stem ™ fits into the small hole in the center of the body. 7. Install o-ring(4) onto the protrusion on the bottom of the M-12 modulator solenoid assembly(2).
- Page 10 TIPS 1. All troubleshooting should begin by performing the “STARTUP,” which focuses on observing the antilock status light on the dash. 2. The troubleshooting technician should record all findings and the action taken during the troubleshooting process. 3. No voltage or resistance tests are performed into the EC-11 controller.
-
Page 11: Troubleshooting
TROUBLESHOOTING INITIAL START-UP PROCEDURE TURN VEHICLE IGNITION ON. OBSERVE AMBER DASH LIGHT. DASH LIGHT FLASHES DASH LAMP DOES NOT DASH LIGHT BLINK, IT COMES ON TWICE AND STAYS ON NOT ON AND REMAINS ON. GO TO SECTION II - ACCELERATE VEHICLE GO TO SEC- INSPECTION ABOVE 10 MPH FOR AT... - Page 12 TROUBLESHOOTING SECTION I - DASH LIGHT TESTING DISCONNECT 14 PIN CONNECTOR FROM ™ EC-11 CONTROLLER OBSERVE DASH LIGHT GROUND DASH LIGHT OFF DASH LIGHT ON RELAY REPLACE EC-11 ™ WITH IGNITION ON, MEASURE VOLTAGE CONTROLLER BETWEEN DASH LIGHT RELAY (PIN D) AND GROUND (PIN C).
- Page 13 TROUBLESHOOTING SECTION II INSPECTION FOR ILLUMINATED LEDS ™ INSPECT EC-11 CONTROLLER FOR ILLUMINATED LED(S) CHECK FOR GREEN (PWR) GREEN (PWR) GREEN (PWR) LED OFF LED ON A R E ARE ANY RED ARE ANY RED A N Y LEDS ON? LEDS ON? REPLACE EC-11 NOTE ILLUMINATED...
- Page 14 TROUBLESHOOTING SECTION III - INSPECTION FOR ILLUMINATED RED LEDS INSPECT EC-15 ™ CONTROLLER FOR PRESENCE OF ILLUMINATED LEDS AND RECORD. VOLT CONT RED SENSOR RED VOLTAGE CONTROLLER MODULATOR LED (SNS) IS LED (VOLT) IS LED (CONT) IS LED (MOD) IS ILLUMINATED ILLUMINATED ILLUMINATED...
- Page 15 TROUBLESHOOTING SECTION IV - INSPECTION FOR ILLUMINATED LEDS IS THE GREEN (PWR) LED ON? MAGNET HERE TO RESET PIN A POWER RECORD INDICATED RED TURN IGNITION OFF. DISCONNECT LED FAILURE (“VOLT” AND/ EC-11 ™ CONTROLLER OR “CONT” 14-PIN CONNECTOR PIN C GROUND TURN IGNITION ON.
- Page 16 TROUBLESHOOTING SECTION V - TESTING MODULATOR RECORD INDICATED MAGNET HERE FAILURE. PERFORM TO RESET A RESET. “MOD” LED “MOD” LED GOES OFF STAYS ON STILL ON? INTERMITTENT CONNECTION DISCONNECT THE 4-PIN ™ BETWEEN EC-11 CONTROLLER CONNECTOR BETWEEN THE AND M-12 ™...
- Page 17 TROUBLESHOOTING SECTION VI PART A - TESTING WHEEL SPEED SENSOR MAGNET HERE RECORD INDICATED FAILURE TO RESET PERFORM A RESET. ANY “SNS” LEDS ON? STILL ON? CHECK FOR OPEN CONNECTOR PRESENCE OF TONE FOR EACH SENSOR RING OR MISSING AND OBSERVE LEDS. TONE RING TEETH CHECK FOR OUT-OF- SPEC SENSOR GAP...
- Page 18 TROUBLESHOOTING SECTION VI PART B - TESTING THE MODULATOR START HERE RESISTANCE OUTSIDE RESISTANCE WITHIN 1500-2500 OHMS 1500-2500 OHMS REPLACE EC-11 ™ DISCONNECT SENSOR FROM WIRE CONTROLLER HARNESS. MEASURE RESISTANCE ACROSS SENSOR PINS. RESISTANCE SHOULD BE 1500-2500 OHMS. REPEAT STARTUP REPLACE CHECK WIRING THAT SENSOR...
- Page 19 TROUBLESHOOTING SECTION VII - FALSE FAILURE INDICATION NOTE: IF DURING STARTUP, THE DASH LIGHT ILLUMINATED WITHOUT BLINKING, GO TO SECTION VII PART B - TESTING FOR FALSE FAILURE CAUSED BY DASH LIGHT RELAY. I F THE DASH LIGHT BLINKED DURING STARTUP BUT ILLUMINATED AFTER THE VEHICLE REACHED 10 MPH, GO TO SECTION VII PART A - TESTING FOR FALSE FAILURE CAUSED BY WHEEL SPEED COMPONENTS.
- Page 20 REPLACE RELAY REPEAT STARTUP, IF IF LIGHT IS TESTING RETURNS TO THIS ON - BAD PLACE TWICE, REPLACE RELAY REPEAT STARTUP THE EC-11 CONTROLLER ™ BW1671 © 2004 Bendix Commercial Vehicle Systems LLC All rights reserved. 4/2004 Printed in U.S.A.